var now = new Date(); //当前日期 
var nowDayOfWeek = now.getDay(); //今天本周的第几天 
var nowDay = now.getDate(); //当前日 
var nowMonth = now.getMonth(); //当前月 
var nowYear = now.getYear(); //当前年 
nowYear += (nowYear < 2000) ? 1900 : 0; // 

var lastMonthDate = new Date(); //上月日期 
lastMonthDate.setDate(1); 
lastMonthDate.setMonth(lastMonthDate.getMonth()-1); 
var lastYear = lastMonthDate.getYear(); 
var lastMonth = lastMonthDate.getMonth(); 

//格局化日期：yyyy-MM-dd 
function formatDate_YMD(date) { 
	var myyear = date.getFullYear(); 
	var mymonth = date.getMonth()+1; 
	var myweekday = date.getDate(); 
	if(mymonth < 10){ 
		mymonth = "0" + mymonth; 
	} 
	if(myweekday < 10){ 
		myweekday = "0" + myweekday; 
	} 
	return (myyear+"-"+mymonth + "-" + myweekday); 
}

function formatDate_YM(date) { 
	var myyear = date.getFullYear(); 
	var mymonth = date.getMonth()+1; 
	if(mymonth < 10){ 
		mymonth = "0" + mymonth; 
	} 
	return (myyear+"-"+mymonth); 
} 

//获得某月的天数 
function getMonthDays(myMonth){ 
	var monthStartDate = new Date(nowYear, myMonth, 1); 
	var monthEndDate = new Date(nowYear, myMonth + 1, 1); 
	var days = (monthEndDate - monthStartDate)/(1000 * 60 * 60 * 24); 
	return days; 
} 

//获得本季度的开端月份 
function getQuarterStartMonth(){ 
	var quarterStartMonth = 0; 
	if(nowMonth<3){ 
		quarterStartMonth = 0; 
	} 
	if(2<nowMonth && nowMonth<6){ 
		uarterStartMonth = 3; 
	} 
	if(5<nowMonth && nowMonth<9){ 
		quarterStartMonth = 6; 
	} 
	if(nowMonth>8){ 
		quarterStartMonth = 9; 
	} 
	return quarterStartMonth; 
} 

//获得本周的开端日期 
function getWeekStartDate() { 
	var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek); 
	return formatDate_YMD(weekStartDate); 
} 

//获得本周的停止日期 
function getWeekEndDate() { 
	var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek)); 
	return formatDate_YMD(weekEndDate); 
} 

//获得本月的开端日期 
function getMonthStartDate(){ 
	var monthStartDate = new Date(nowYear, nowMonth, 1); 
	return formatDate_YMD(monthStartDate); 
} 

//获得本月的停止日期 
function getMonthEndDate(){ 
	var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth)); 
	return formatDate_YMD(monthEndDate); 
} 

//获得上月开端时候 
function getLastMonthStartDate(){ 
	var lastMonthStartDate = new Date(nowYear, lastMonth, 1); 
	return formatDate_YMD(lastMonthStartDate); 
} 

//获得上月停止时候 
function getLastMonthEndDate(){ 
	var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth)); 
	return formatDate_YMD(lastMonthEndDate); 
} 

//获得本季度的开端日期 
function getQuarterStartDate(){ 
	var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1); 
	return formatDate_YMD(quarterStartDate); 
} 

//或的本季度的停止日期 
function getQuarterEndDate(){ 
	var quarterEndMonth = getQuarterStartMonth() + 2; 
	var quarterStartDate = new Date(nowYear, quarterEndMonth, getMonthDays(quarterEndMonth)); 
	return formatDate_YMD(quarterStartDate); 
} 